Reactive arthritis and Reiter’s disease

Reactive arthritis and Reiter’s disease:

Reactive arthritis is predominantly a disease of young

men with a sex ratio of 15:1. It is the most common cause

of inflammatory arthritis in men aged 16–35 but may

occur at any age. Between 1 and 2% of patients with nonspecific

urethritis seen at genitourinary medicine clinics

have reactive arthritis. Following an epidemic of Shigella

dysentery, 20% of HLA-B27-positive men developed

reactive arthritis.

Clinical features

The onset is typically acute or subacute, with an inflammatory

oligoarthritis that is asymmetrical and targets

lower limb joints, typically the ankles, midtarsal joints,

metatarsophalangeal joints or knees. Achilles tendinitis

or plantar fasciitis may also be present. There may be

considerable systemic disturbance with fever and weight

loss. It occasionally presents subacutely with single joint

involvement and there may be no clear history of an infectious

trigger. The first attack of arthritis is usually selflimiting,

with spontaneous remission within 2–4 months.

However, recurrent or chronic arthritis develops in

more than 60% of patients. Low back pain and stiffness

are common and 15–20% of patients develop spondylitis.

Around 10% of patients have evidence of active disease

20 years after the onset. Spondylitis, chronic erosive

arthritis, recurrent acute arthritis and uveitis are the

major causes of long-term morbidity.

Extra-articular features 

Circinate balanitis starts as vesicles on the coronal margin

of the prepuce and glans penis, later rupturing to form

superficial erosions with minimal surrounding erythema,

some coalescing to give the circular pattern. Lesions

are often painless and may escape notice. Keratoderma

blennorrhagica begins as discrete waxy yellow-brown

vesico-papules with desquamating margins, occasionally

coalescing to form large crusty plaques. The palms and

soles are particularly affected but spread may occur to

the scrotum, scalp and trunk. These lesions are indistinguishable

from pustular psoriasis. Nail dystrophy with

subungual hyperkeratosis is common and indistinguishable

from psoriatic nail dystrophy. Mouth ulcers manifest

as shallow red painless patches on tongue, palate, buccal

mucosa and lips, lasting only a few days. Conjunctivitis

may accompany the first acute episode. Uveitis is rare

with the first attack but occurs in 30% of patients with

recurring or chronic arthritis.

Other complications are rare but include aortic incompetence,

conduction defects, pleuro-pericarditis, peripheral

neuropathy, seizures and meningoencephalitis.

Investigations

The diagnosis is usually made clinically but joint aspiration

may be required to exclude crystal arthritis and

infection. Synovial fluid is inflammatory and often contains

giant macrophages (Reiter’s cells). ESR and CRP

may be raised. Urethritis may be confirmed in the ‘twoglass

test’ by demonstration of mucoid threads in the

first-void specimen that clear in the second. High vaginal

swabs may reveal Chlamydia on culture. Except for post-

Salmonella arthritis, stool cultures are usually negative

by the time the arthritis presents, but serum agglutinin

tests may help confirm previous dysentery. RF, CCP and

ANA are negative.

X-rays are seldom helpful during the acute attack,

but in chronic or recurrent disease periarticular osteopenia,

joint space narrowing and marginal proliferative

erosions may be observed. Another characteristic

feature is periostitis, especially of metatarsals, phalanges

and pelvis, and large ‘fluffy’ calcaneal spurs. In

contrast to AS, radiographic sacroiliitis is often asymmetrical

and sometimes unilateral, and syndesmophytes

are predominantly

coarse and asymmetrical,

often extending beyond the contours of the annulus

(‘non-marginal’)

. X-ray changes in the

peripheral joints and spine are identical to those in

psoriasis.

Management

The acute attack should be treated with limited rest, oral

NSAIDs and analgesics, and for marked synovitis, intraarticular

injection of corticosteroids. Non-specific

chlamydial

urethritis is usually treated with a short course

of tetracycline and this may reduce the frequency of

arthritis in sexually acquired cases. Treatment with

DMARDs should be considered for patients with persistent

marked symptoms, recurrent arthritis or severe keratoderma

blennorrhagica. Anterior uveitis is a medical

emergency requiring topical, subconjunctival or systemic

corticosteroids.